Method and apparatus for producing sheet-like material



April 17, 1934.

W. 5. KING 1,955,503 METHOD AND APPARATUS FOR PRODUCING SHEET LIKEMATERIAL Filed April 7, 1930 l 5 IL ll ll I]! III 1r 1f.

LEI ELER. CONVEYOR. V CO LD ROLL/[VG MILL.

6- x9 7 I, J0

noL LING MILL. I I P/CHL ER. LEI/[L m. SCRUEBER. 0R YER.

CONVEYOR.

Patented Apr. i7, lQB i METHOD AND APPARATUS FOR PRODUCING SHEET-LIKEMATERIAL Welty S. King, Youngstown, Ohio Application April 7, 1930,Serial No. 442,324

9 Claims. (Cl. 29--l8) The present invention relates broadly to the artof producing sheet material, and more particularly to a method andapparatus for producing such material by a rolling operation.

At the present time, due to the many advantages obtainable by the use ofso-called cold rolling mills, their use has very appreciably increased,so that they now constitute a very important part of the sheet'a-ndstrip mill equiplll ment. Experience gained from the use of such coldrolling mills has shown a tendency to produce defects commonly referredto by operators as spreaders, flowers and squeezers. These defects arecharacterized by a vein-like and some- 315 what irregular series oflines of depression-on the surface of the material. These defects areusually more pronounced in the direction of rolling, and it is believedthat they are caused either by a non-uniform extension or compression of29 the material during the cold rolling operation.

While such lines of depression are extremely shallow, they are ofsufficient depth to be detrimental to the appearance of the fullfinished sheets such as those used in the automotive industry, for

metal furniture, or for other purposes in which a high degree of finishis required.

In partial explanation of the present invention, if a section of a sheetbe considered in a microscopic sense, it will be noted that the elasticlimit -9 of different adjacent sections is not uniform over the entiresurface. I'his may be easily shown by subjecting a sheet to a so-calledstretcher leveling operation wherein the sheets are gripped at theopposite ends by mechanical means and 3 stretched until a desired degreeof flatness is obtained. It will be noted that such an operation ifeffected substantially immediately after hot rolling, annealing ornormalizing, will result in lines of depression in a direction at rightangles 40 to that of stretching. These may be explained as resultingfrom the tendency of numerous portions of the sheet to undergo extensionor yielding in advance of other portions, thereby resulting in a slightnecking down of the metal at -5 such points, this necking down appearingas lines of depression on the sheet surface, and ordinarilycharacterized as stretcher strains. Such necking down is progressive,beginning with the portions of lowest elastic limit and grad-' uallyextending to portions of higher and higher elastic limit.

By subjecting the metal to a roller leveling operation prior to coldrolling, the material is mildly worked, the

degree of hardening, which in turn tends to working resulting in aslight equalize the elastic limits of adjacent sections, therebyresulting in the production of a sheet having a more nearly uniformelastic limit throughout the entire sheet, whereby subsequent coldrolling will affect the sheet substantially the 59 same in all of itsportions.

I have found that this phenomena, due either to such non-uniformextension or compression, is present in cold rolling such material ashot rolled sheets, annealed sheets or normalized sheets, and that in allsuch material the defects previously referred to as Spreaders, flowersand squeezers will be produced.

I have further found that the tendency to form such defects during coldrolling can be ma- 'terially decreased if not completely obviated by asuitable roller leveling operation just prior to the cold rolling. Inthis connection, however, experience has shown that if the sheetmaterial is roller leveled and allowed to stand, say for ex- 7 ample fora periodof 24 hours, before being subjected to a cold rolling operation,substantially if not quite all of the beneficial effects of the rollerleveling operation are lost or negatived to such an extent that thedefects before referred 0 to will form during cold rolling much the sameas though no roller leveling operation had been resorted to. It istherefore not only desirable, but essential, if the maximum degree ofbenefit is to be maintained, to cold roll the sheet material as soon aspossible after the roller leveling operation. To this end, the inventionis preferably practiced by effecting a continuous or substantiallycontinuous movement of the sheet material from the time of rollerleveling to the time of cold rolling. J

The present invention provides a method and apparatus by means of whichit is possible to eliminate defects of the character referred to andobtain at the same time a minimum handling of the material with aconsequent economy of production.

In the accompanying drawing I have shown for purposes of illustrationonly certain preferred embodiments of the invention, by means of whichthe desirable results herein referred to may be accomplished.

In the drawing, Figure 1 is a diagrammatic plan view illustrating aroller leveler and cold rolling mill in such position as to permitroller leveling of sheet material followed by a cold rolling operation,

Figure 2 is a diagrammatic plan view illustrating a slightly modifiedembodiment of the invention effective for obtaining pickling, rollerleveling, scrubbing, drying and cold rolling of sheet material, and

Figure 3 is a view similar to Figure 2 illustrating a layout effectivefor pickling, scrubbing, drying, roller leveling and than cold rollingthe sheet material.

It will be understood by those skilled in the art that the expressionsheet material is herein used generically as definitive not only of sucharticles of manufacture as ordinarily designated sheets, but of similarmaterial in more or less strip form, the invention being applicable tosuch materials broadly without regard to the specific dimensions or formthereof.

In the embodiment of the invention illustrated in Figure 1 of thedrawing, there is provided a roller leveler 2 of any desiredconstruction through which the material passes in the directionindicated by the arrow 3 onto suitable skids or conveying means 4effective for feeding the material directly to the roll pass of a coldrolling mill 5. By such a layout, it will be apparent that the materialis subjected to a cold rolling operation immediately following theroller leveling operation.

In .the ordinary practice of roller leveling sheets, four men arerequired, these men usually being designated as a flopper a feeder andtwo catchers. Inasmuch as the usual 'cold rolling operation requires twomen at the entering side of the cold rolling mill, it will be apparentthat not only does the present invention enable defects of the characterreferred to to be eliminated from sheet material, but it effects aco-ordination of a roller leveler, and cold rolling mill such as todecrease the total number of operatives required for their operation.This is true for the reason that the two men usually positioned at theentering side of the cold rolling mill are simply moved to a position infront of the roller leveler for starting the sheet material therethroughrather than through the mill. After passage through the roller leveler,the material passes automatically, by reason of skids or other conveyingmeans, directly into the mill.

Experience in the practice of cold rolling sheet steel has shown thatcertain desirable properties of the sheets are enhanced by so calledrolling in oil. By this is meant a rolling operation includingcompletely coating the sheets with a light covering of oil before theyare entered between the cold rolls. In some practices this coating ofoil is applied by a common type of oiler with felt rolls, the sheetsbeing either passed from the oiler directly into the cold rolls orstacked on the floor before cold rolling. Such a practice, however,possesses at least two disadvantages. The first of these is due to thetendency of small particles of felt to adhere to the sheets, whichparticles seriously damage the fine surface of full finished sheetsduring the subsequent cold rolling operation. The second disadvantage isthe tendency of dust and dirt to quickly accumulate on the oiledsurfaces of the sheets when piled in stacks. Such accumulations arelikewise objectionable for the reason that they will mar the sheetsurfaces during the cold rolling operation.

In accordance with the present invention, the roller leveler placed inline with the cold rolls is also conveniently used as an oiler. This maybe accomplished by oiling the sheet material at the same time that it isbeing passed through a roller leveler. After passing through such an oiing roller leveler, the sheet material is free from dirt and lint forthe reason that the roller leveler rolls are clean and free from dirtand therefore enable the maintenance of a clean surface on the material.Since the material passes in continuous operation from the oiling rollerleveler into the cold rolls, it is not afforded any opportunity for dustor dirt accumulation on the material.

In the embodiment'of the invention illustrated in Figure 2, there isindicated a suitable pickling vat 6 from which the pickled sheets passto a roller leveler '7 and thence through a scrubber 8 and a dryer 9 tocold rolls 10. It will be apparent that the time which elapses from theroller leveling operation to the cold rolling operation is not such thatthe beneficial effects of roller leveling are lost.

In the embodiment of the invention illustrated in Figure 3, the sheetmaterial pickled in a suitable pickling vat 11 passes through a scrubber12 and a dryer 13 to a roller leveler 14 and thence to the cold rolls15. With this embodiment of the invention it will be apparent that theroller leveler may be used also as an oiler in the manner described inconnection with Figure 1, with all of the advantages hereinbeforereferred to.

To those skilled in the art it will be apparent that not only does thepresent invention provide convenient means for the effective handling ofmaterial of the character herein contemplated, but that it also enablessuch material to be subjected to the desired cold rolling operationwithin such a time interval after the roller leveling, as to insure theobtaining of maximum benefits. In actual practice I have found that itis possible to reduce surface defects of the character referred to tosuch an extent that a saving of from 1 to 3% is obtained under ordinarymill conditions. One economy of the layout alone, in addition to thesuperior sheets produced, results in a substantial labor saving per tonof material.

Certain advantages of the invention arise from the step of subjectingsheet material to a roller leveling operation immediately orsubstantially immediately preceding a cold rolling operation.

Still further advantages arise from the utilization of the rollerleveler as an oiler whereby the sheet material before entering the coldrolls is provided with an oil coating.

Still other advantages of the invention result from the combination of aroller leveler and cold rolling mill in such manner that the twooperatives usually required at the entering side of the cold rollingmill may serve the function of feeders for the roller leveler, which inturn serves as an automatic feeding means for the cold rolling mill.

Other advantages of the invention will be apparent to those conversantwith the production of sheet material of the character herein referredto and with the operation of mill equipment for the production of sheetmaterial, it being understood that changes in the construction andarrangement of the various mechanisms herein referred to may be madewithout departing either from the spirit of the invention or the scopeof my broader claims.

I claim:

1. In the method of producing sheet material, the steps comprisingsubjecting the material to a roller leveling operation followed by acold rolling operation, andapplying a liquid film of oil to the materialprior to the cold rolling operation.

2. In the method of producing sheet material, the steps comprisingpassing the material substantially continuously through a roller levelerand a cold rolling and applying a film of oil to the material prior toits entry into the cold rolling s. In a rolling mill, the combinationwith a cold rolling mill, of an oiler roller leveler in advance thereofeffective for roller levelling and oiling material during its passage tothe cold rolling mill.

i. In a rolling mill, a cold roll mill stand, means in the feed path tosaid stand for simultaneously subjecting material to a roller levelingand oiling operation, and means for passing the leveled and oiledmaterial to the cold roll mill stand.

5. In a mill, a cold roll stand, means for pickling sheet material insequence and substantially continuously, and means for subjecting thepickled materiai to a roller leveling operation and then cold rolling.

e. In the method of producing metallic material, the steps comprisingsubjecting the metal to a mild working by roller levelling to unify theelastic limit throughout the entire body thereof, and thereafter coldrolling the same within such a time interval as to retain the beneficialeffects of the levelling operation.

'7. In the method of producing metallic material, the steps comprisingsubjecting the metal to a mild working by roller levelling for slightlyhardening the same and equalizing the elastic limits of adjacentsections of the metal prior to a cold rolling operation, and thereaftercold rolling the same within such a time interval as to retain thebeneficial effects of the levelling operation.

8. In a sheet mill, means for imparting a final finish to sheets, andmeans for preparing the sheets i or finishing including a pickler and aroller leveler disposed to operate on the sheets sequentially and priorto the final finishing.

9. In a sheet mill, at final stand of cold rolls imparting a finish tothe sheets, and means for preparing the sheets for the cold roll standincluding pickling means and leveling means so disposed adjacent saidstand as to operate on the sheets sequentially and prior to said stand.

WEL'I'Y S. KING.

